Abstract: The invention relates to apparatus for positioning and holding a screen carrier in a serigraphic machine. The positioning and holding apparatus is essentially constituted by two parallel grooves (21, 22) machined in the screen carrier (10) and cooperating stops and a side latch mechanism on the machine. The two grooves have at least one extremity opening on the same edge (C1) of the screen carrier. In these two grooves (21, 22) are respectively mounted the two stops (23, 24) which are designed to come respectively into contact with two fixed reference pins carried by the serigraphic machine. During insertion of the screen carrier, by sliding in its plane along two sides of the serigraphic machine, the two reference pins ride in the respective slots contacting the stops when the screen carrier is inserted fully. A latch locking arrangement is provided on the machine or maintaining and holding the screen carrier in position once the reference pins are in contact with the associated stops.

Abstract: A process and an apparatus for automatically positioning a piece on a worktable. A worktable (4) supports a reference system (3) constituted by three rollers (G1, G2, G3). The piece such as a substrate (2) is placed on the table (4) in the neighborhood of the rollers. A first pivoting arm (21) comes into contact with a side (C3) of the substrate (2) to bring the opposed side (C1) in contact with the rollers (G1, G2). A second pivoting arm (20) comes into contact with the side (C4) of the substrate (2) to bring the opposed side (C2) in contact with the roller (G3). The arms (20, 21) are controlled by a single means such as a jack (22) of which the body (23) and the rod (24) are floatingly mounted and are respectively associated with the two arms (20, 21). The invention is primarily useful for positioning of a support for integrated circuits in a serigraphic machine.